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GB For Salas DCG-3 and DCSTB Power Supplies

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This is the official GB thread for the DCG-3 and DCSTB Power supply boards.

The DCG-3 is a JFET and MOSFET, 2 stage-single ended preamplifier/headphone amp
The preamplifier uses a DC Servo and three MOSFETs, hence the name DCG-3.

DCG3protoPicG1.png


There is also simple series DC stabilizer designed to compliment the circuit. It is called the DCSTB board. It is of mirrored Configuration and is sized to fit in same width footprint as the preamplifier board. A BIB SSLV1.1 board or other regulator can be used as well, if you know how to set to 17.5V recommended voltage as well.

DCSTBv1_G.png


The main construction thread is located below. Most technical questions should be approached there.

Salas DCG3 preamp (line & headphone)

For selling and delivery purposes, this thread will do.

The costs for the DCG-3 board is 20.00, and 25.00 for the DCSTB Power supply.
DCG3andDCSTBboardspicG1.png

Additionally, Transistor kits are available for components that need matching and can be seen in detail in the later part of the my kit blog

Salas Board Minikits and Full Kits - diyAudio

Here is a picture of my prototype running.
image5_1_.jpeg


Board sizes are
DCG-3 -160x50mm
DCSTB- 160x106mm

The sign up sheet is in my signature for these boards, and are located on the right of the spreadsheet. Once enough boards are in demand, I will post the GB close date on this thread and in my signature. You should also receive a private message if you have signed up on the thread.
 

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For the DCSTB Full kit (No board, includes trans.) per side $40, do I need to order one, or two for the board?

Jim

You need to order two of them. I did this to keep the costs in check, as it is substantially more money to build a fully loaded dual mono setup in both transformers and parts. The heatsinks are painfully expensive to ship and caps, and so some of that is reflected in the shipping.

I will need a consensus if people plan to build using dual mono or one PS, if it's one power supply, in the final throws of the GB, I will need to change the fuses and diodes. They both costs a bit more. Still figuring that point out.
 
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????

Would you guys prefer TO-220 MSRF860G for all diodes? It will be needed for using one DCSTB to run a DCG-3. It's easier to stock, and but cost doubles for the diodes. If everyone runs dual mono, then diode and fuse stock needed can be minimized. Let me know
 
Forgot the most important reasons for buying your Group Buy kits. You make better parts choices than I do. I always learn from your kits. I also end up completing the project in a reasonable time as you have sent me the hard to get parts. Some of my projects wait forever. Too many times I have needed to order one more part but can't bring myself to make a $5 order and pay for shipping and customs on top.

What ever works best for you.

Jim
 
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Tea,

I already have an In-Select board that will go in this preamp but am wondering if I need to be extra careful with transformer choice for the In-Select relays. Don't want it spreading hum around. What do you recommend?

Jim

I am not Tea, but here's an idea

That selector board has options and connectors. AC or DC powered. Run a straight DC feed to the selector board from a DCSTB's positive rail. Don't even populate the selector's rectifier diodes and use a 100uF capacitor for decoupling instead of its 2200uF reservoir. Not even a sink for the 7812. One relay only will be engaged for connecting an input. Talking just 10mA. Look in my preamp, no extra transformer. A DC feed +/0 twisted pair travels under the double floor and emerges under the selector's board DC in. OK it does not always have to be a Paris sewers ghost :D It can simply get nicely dressed on the surface and be better serviceable too.
 

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Hi Tea-Bag,

I have 2 ADA4627 (FET input) on Browndog, can I substitute the servo opamp with it?
If it is possible, can I sign-up a transistor kit without the the costly servo opamp?
Sorry if there is any inconvenience caused. :)

Sorry, I do not make kit substitutions. It makes kit making and filling orders very complicated. The kit comes with a socket, so you may be able to try both if they are compatible.